In simple manually operated toothbrushes without motor drive, it is well known to not only flexibly construct the brush handle but also the brush head itself with the attached bristles so as to achieve better adaptation of the working surface defined by the bristles, to the contours of the teeth. In some cases the brush head is divided into several segments which are interconnected by transverse bridges made from elastic rubber, so that the segments can undergo torsional flexing in relation to each other (compare, for example, German patent publication 198 31 412 A1 and PCT publications WO 98/27846 and WO 96/02165). The torsional flexibility of the brush head makes it possible for the working surface, which is defined by the free ends of the bristles and concave in the initial state, to be changed into an essentially planar working surface as the bristles are pressed against the teeth.
However, in generic brush heads for motor-driven toothbrushes, it is more common to find rigid bristle supports in the shape of a disc, to which the bristle tufts are rigidly attached. In contrast to manual toothbrushes, such brush heads typically carry out a rotary movement, either continuously or in an oscillatory manner, on an axis of rotation that is essentially perpendicular to the bristle Support disc. For improved adaptation of the working surface to the contours of the teeth and for improved interdental cleaning, a different approach has been taken for brush heads of motor-driven toothbrushes. For example, bristle tufts that are inclined at an angle toward the direction of rotation have been proposed, the bristle tufts being intended to enter the interdental spaces. See, for example, European patent 0765642. Furthermore, rotatable brush arrangements with bristle tufts arranged parallel to the axis of rotation have been proposed, with the bristles of such arrangements being of a length suitable to form an approximately cone-shaped working surface that is intended to facilitate cleaning in interdental spaces. See, for example, U.S. Pat. No. 5,862,559.
It has also been proposed to drive the bristle tufts relative to each other. U.S. Pat. No. 5,500,970 shows a non-generic brush head for a toothbrush, the brush head having(arms that are arranged in a V-shape, with bristle tufts attached to the arms. The bristle tufts that are directed towards each other encompass the teeth in a pliers-like manner. A corresponding drive moves the arms towards each other and away from each other so that the bristle tufts carry out corresponding cleaning movements on the tooth faces situated between them. However, the tooth-like arrangement of the bristle tufts prevents a rotary drive movement of the bristles that can be desirable for proper cleaning of the chewing surfaces of the teeth.
Generic brush heads for motor-driven toothbrushes with a rotary drive arrangement thus continue to require improvement in both proximal and interdental cleaning. In particular, comprehensive cleaning of all dental regions, including the molars, premolars and incisors, can be improved.
It is thus the object of the present invention to create an improved toothbrush of the type mentioned above, to create an improved brush head for this sort of toothbrush, and to provide advantageous improvements to the state of the art. In particular, a brush head for motor-driven toothbrushes with rotary drive movement is to be improved for thorough proximal and interdental cleaning.